Code of Federal Regulations Title 46. Shipping § 46.161.013–9 Independent power source

(a) Each independent power source must be capable of powering the light so that it meets the requirements of § 161.013–3(a)(1) and emits a recognizable flash characteristic of the International Morse Code for S–O–S at a rate of between 3 and 5 times per minute after six hours of continuous display of the signal.

(b) If the independent power source is rechargeable, it must have a waterproof recharger designed for marine use.

(c) If the independent power source requires external water to form an electrolyte, it must operate in sea water and fresh water.